Scavenging mechanism for two-cycle engines



Oct. 4, 1932. BAUER 1,880,674

SCAVENGING MECHANISM FOR TWO-CYCLE ENGINES Filed Nov. 5, 1926 2 Sheets-Sheet 1 Inventor:

Oct. 4, 1932. BAUER 1,880,674

SCAVENGING MECHANISM FOR TWO-CYCLE ENGINES Filed Nov. 5, 1926 2 Sheets-Sheet 2 INVENTOR 011x500 fiuaer ATTORNEYS Patented Oct. 4, 1932 PATENT OFFICE GUSTAV BAUER, F HAMBURG, GERMANY SCAVENGING MECHANISM FOR TWO-CYCLE ENGINES Application filed November 5, 1826', Serial No. 146,549, and in Germany March 4, 1928.

My invention relates to mechanism for driving the scavenging air pumps of twocycle internal combustion engines, and particularly in power plants where the engine is 5 used for the propelling of vessels, vehicles,

and the like.

Efi'orts have long been made to render the power plants of vessels and vehicles as economical as possible and to utilize to the fullest capacity the engines designed for and used in such power plants. Special efforts have been made to utilize as few engines as possible for driving the auxiliary machines which cooperate in any way with the main engines of the propelling power plant, and to render as simple as possible the entire arrangement and combination of the engines and machines constituting the power plant. To secure this object it has been customary to drive such auxiliary machines, as far as possible, from the main engines, while the latter are'operating to propel the vessel or vehicle. With such arrangements it is necessary to provide separate engines for the auxiliary machines for use when the main engines are not running. Therefore it is necessary to provide means for uncoupling the auxiliary machines from the main engines.

80 Two-cycle internal combustion engines require scavenging air pumps, and it is customary to provide separate engines of such size that the pumps may deliver such large amounts of air as are required when the load on the main engines is at its maximum.

The main object of the present invention is to overcome the difficulties which have heretofore been encountered, and as one of the main features of the present invention, I

* employ liquid couplings between the main engine and the air pump, and employ the main engine for driving the air pump through said liquid couplings.

The type of coupling preferably employed is that known as the Fottinger or Vulcan coupling, and shown and broadly claimed in the Fottinger Patent 1,199,359, dated Sept. 26, 1916. Couplings of this type are especially suited for the purpose as the transmission of power through them can be stopped or started easily and free from shocks by the withdrawal of liquid from or the delivery of liquid to the coupling during the rotation of the driving part.

As an advantage of my improved construc- 55 tion, it is possible to speed up the air pumps by means of gearing so that air pumps of smaller size can be used than is otherwise possible.

The liquid coupling and the gearing may 0 be disposed at the front end of the engine, whereby there is obtained the further advantage that the coupling, gearing and pump can be utilized as masses tending to damp the torque variations of the engine shaft, 0 whereby more uniform running of the engine is obtained.

In plants in which two or more internal combustion engines are employed for driving the main shaft through liquid couplings and 79 speed reducing gearing, the air scavenging pump may be driven by the shaft of the pinion of the gearing which drives the gear of the main shaft. The arrangement and combination of parts can be such that other auxiliary machines, for instance a motor generator, a compressor or other pumps, can be driven by the same shaft that drives the scavenging pump. Thus the motor generator may serve'as a dynamo when the main engine is running and may serve as a motor for operating the scavenging pumps when the main engines are at rest. Thus the scavenging pumps may be operated for compressing air or for scavenging either when the main engine is running or when it is at rest.

In the accompanying drawings there are illustrated somewhat diagrammatically certain constructions embodying my invention.

In these drawings:

Fig. 1 is a plan view, partly in section, of a plant embodying the invention.

Fig. 2 is a plan view of a portion of a plant, showing a somewhat difi'erent arrangement, and

Figs. 3 and 4 are plan views of still further forms.

In the arrangement illustrated in Fig. 1, there are provided two oil engines 1 of the mo electric machine.

two-stroke cycle type, each having a dri e shaft 2 driven from the pistons of a plurality of working cylinders 3. Each engine has a compressor 4 located at the end thereof. The shafts 2 are connected by hydraulic couplings 5 of the Fottinger or Vulcan type to corresponding aligned shafts 6, and the latter are provided with pinions 7 meshing with opposite sides of a large gear 8 on the main drive shaft 9. One half of each liquid coupling is connected to the engine shaft 2, while the other half is connected to the driven shaft 6.

Suitable means are provided for facilitating the emptying or filling of the couplings to vary the amount of power transmitted to the driven shafts, or the speed thereof. The specific construction of the liquid couplings forms no portion of my present invention, and the filling and emptying means may be effected in any suitable manner. Merely as an example of control means for the liquid outlets, I call attention to Patent 1,613,154, dated Jan. 4, 1927, to Bauer and Wiilde.

Each engine is provided with an air scavenging pump 13 which may deliver to a manifold 13' connected by branch conduits 13" to the several working cylinders of the engine. Each pump has its shaft 12 connected to a pinion 17 meshing witha gear 16 on the periphery of the driven section of a hydraulic coupling of the Fottinger or Vulcan type. The driving section of the liquid coupling 11 is connected to a shaft 18 which forms an extension of the main engine shaft 2, or

which is directly secured thereto by a suitable flange coupling 10. The liquid coupling may be filled and emptied by any suitable means,

such as shown in the Bauer and Waldo patent above referred to.

It will be understood that the shaft 12 of the scavenging air pump may be employed for driving other auxiliary machines, and moreparticularly may be coupled to a dyna- Such a dynamo electric machine is shown in Fig. 2. In Fig. 2 the liquid coupling is shown on a somewhat larger scale, but somewhat diagrammatically, the driving section 14 of the coupling being connected to the shaft 2 and the driven section 15 being secured to a shaft 19 mounted in a suitable bearing 20.

The same bearing block 20 supports the shaft 18 which carries the pinion 17, meshing with the gear 16 on the driven section of the liquid coupling. The shaft 18 extends in opposite directions from the bearing and has the scavenging air pump 13 connected to one end and a dynamo electric machine 22 connected to the opposite end by an ordinary flange coupling 21.

When the engine is at rest, the liquid may be withdrawn from the coupling and the scavenging air pump may be operated directly by the dynamo electric machine 22 acting as a motor. When the main en ine is operating, the liquid coupling will e filled so as to transmit power through the coupling and speed increasing gearing to the shaft 18, and drive both the scavenging air pump and the dynamo electric machine so that the latter will operate as a generator.

In Fig. 3 the construction is similar in most respects to that illustrated in Fig. 1, except that in addition to the liquid coupling 5 there is provided an additional liquid coupling 25 for transmitting power to the main shaft 9. The driving halves of each coupling (right hand side of coupling 5 and left hand side of coupling 25) are connected to the shaft 2, while the driven halves of the two couplings (left hand side of coupling 5 r and right hand side of coupling 25) are connected to opposite sides of the pinion 7. One of the couplings is arranged for forward driving of the pinion and the other for driving it in the reverse direction, one coupling being filled when the other is empty. The coupling 11 is also shown as a separate element from the gear 16, instead of being housed within the latter, and an additional pump 23 is shown as connected to the shaft of the scavenging air pump 13.

The construction shown in Fig. 4 is similar to that shown in Fig 3, except that instead of employing a liquid coupling 11 for transmitting power to the gear 16 a liquid coupling 24 is employed for transmitting power from the pinion 17 to the shaft of the scavenging air pump 13. In both cases the speed increasing gearing and the liquid coupling are in series, but in the arrangement shown in Fi 4 a smaller liquid coupling may be use because operating at lower speed.

I have shown the scavenging air pump and its drive, at the front or right hand end of the engine in Figs. 1 and 2, but it will be evident that it might be arranged at the opposite end and connected to the shaft 6.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In combination, a two-cycle internal combustion engine, a scavenging air pump for delivering scavenging air to said engine, and connections between said engine and said pump for driving the latter, and including a speed increasing gearing and a liquid coupling in series.

2. A power plant for vessels, vehicles and the like, including a two-cycle internal com bastion engine, a scavenging air pump at one end of said engine for delivering scavenging air to said engine, a main driving shaft connected to said engine at the opposite end of the latter, and driving connections between said engine and said scavenging air pump,

including speed increasing gearing and a liquid coupling arranged in series.

3. A power plant for vessels, vehicles and the like, including a two-cycle internal combustion engine, a scavenging air pump at one end of said engine for delivering scavenging air to said engine, a main driving shaft connected to said engine at the opposite end of the latter, driving connections between said engine and said scavenging air pump, including speed increasing gearing and a liq uid coupling arranged in series, and driving connections between said engine and said driving shaft, including speed reducing gearing and a liquid coupling arranged in series.

4. In combination, a two-cycle internal combustion engine, a scavenging air pump for delivering scavenging air to said engine, connections between said engine and said pump for driving the latter, and including a speed increasing gearing and a liquid coupling in series, and a dynamo electric machine connected to said scavenging air pump and serving to drive said pump when said coupling is empty and to be driven by said engine when said coupling is filled.

5. A power plant for vessels, vehicles or the like, including two two-cycle internal combustion engines, a drive shaft, speed reducing gearing and a liquid coupling con nected in series between each of said engines and said drive shaft, separate scavenging pumps for said engines, and speed increasing gearing and a liquid coupling connecting each of said pumps to its corresponding engine.

In testimony whereof I afiix my signature.

GUSTAV BAUER. 

